In ancestral times, physical prowess was more important than it is today because it indicated greater survival capabilities. Therefore, physically-based social competition was commonplace.

Interestingly, this competition seems to have laid the groundwork for nurturing and cooperation, according to evolutionary psychologists David Geary and Mark Flinn 1. But these drives may also be responsible for certain types of anxious and depressive responses.

Monkey Studies and Environmental Causes of Low Serotonin

Many primate groups maintain heirarchies with one (or a pair of) individuals at the top of the stack. These groups are not formed because the animals in question talked it out and decided in a democratic fashion who would be their leader (though it could be argued that a bunch of trained monkeys would be better suited to Congress than our current elected officials).

But serotonin alters more than competitive drive. It leads to depressive states and anxiety as well as changes in personality traits like extraversion. But why would we evolve to experience changes in mood instead of trying to better our lot? Shouldn't we want to compete? How could depression possibly be adaptive?

The Drive Towards A More Social Existence

Geary and Flinn report that when moving from an ancestral family group with one male, to a group including many males and females, there needed to be more cooperation in the realm of breeding and resource sharing. Thus, there evolved a hierarchy with several of the strongest males and females on the top of the social ladder. These individuals would have more access to resources should food become scarce, as well as the most desirable mating opportunities. In addition, those of higher rank would have had the greatest access to assistance from alternative caregivers3, according to Sarah Blaffer Hrdy, author of Mothers and Others.

Even today, quality babysitters and nannies remain in short supply and high demand, hence your desire to punch the neighbor who scored the last New Years Eve sitter.

"Damn you, Judy!"

Group Living as a Cause of Depression and Anxiety

This new way of living led to additional changes in the way we interacted. In a study entitled "Territory, Rank and Mental Health", researchers explored the ways anxiety evolved through this type of competitive strategy2. They reported that as the tribes or groups became larger, anxiety and depression became important to the survival of the group.

In small groups, a conflict can be solved by one primate killing another or by the loser running away from the area. To the winner go the spoils.

"You better run, sucka!"

However, larger group sizes meant that both the winner and loser of the contest had vital roles to preform, and thus remained together after the initial competition was over. The necessity of all to live together gave rise to submissive behavior (deescalation) which was generally categorized by the loser showing anxiety and fear of the winner, lowered mood and lowered self-esteem. Instead of outright violence, we began to embrace emotional beatings. Low serotonin, in the form of anxiety and depression, stabilized group living by ensuring that members of the group would not constantly challenge one another, leading to less aggression overall and higher rates of survival for everyone.

It's hard to find the motivation to fight when you're depressed.

The study went further to conclude the following:

"...at the emotional level, escalation is less dramatic than the anger of agonistic competition; it takes the form of exhilaration, enthusiasm and self-confidence. Deescalating reflects the fact that punishment comes from the group rather than from a dominant individual, so there is social anxiety, guilt and shame. This is an appeasement display to the group, expressing contrition for breaking group rules, or for failing to come up to group standards."2 (pp540)

In other words, winners feel superior. Those who think they are fulfilling their roles within the boundaries of their group should feel happy and powerful with high self-esteem. Those who believe they have not managed to live up to group standards, or who have broken the rules of the group, should be expected to have depression, anxiety and lowered self-worth.

Does this sound familiar? Social anxiety and shame for the belief, no matter how unfounded, that you have somehow failed to live up to the standards of those around you?

Thanks to Pinterest posts by our closest friends, we can feel this way every day.

"I mean who turns their kids' lunches into art? I suck."

With so many different groups, and standards within them, we have all kinds of things to feel badly about. At least we have a very good evolutionary reason to be receptive to shame and guilt.

Despite strong evidence for the existence of these drives, no one theory explains everything and multiple factors alter how underlying traits show up in individuals. While this drive may not be the entire story, understanding it may help people to identify more concrete triggers to unwanted feelings and address them. While it may be harder to avoid when the source of the shame is a spouse or other loved ones, recognizing the significance of the emotions can at least make us feel slightly less anxious about having them in the first place.

Topic-Relevant Resources

Mothers and OthersAnthropologist Sarah Blaffer Hrdy explores the history of maternal drives and assistant caregivers

Listening to ProzacThe effect of serotonin and other neurotransmitters on personality and mental health, and the changes in diagnosis itself with the introduction of medications for the "less mentally ill"

Darwinian PsychiatryDetailed evolutionary explanations of the roots of clinical diagnoses from depression to eating disorders to personality issues.

Recommended Stuff

Listening to ProzacThe effect of serotonin and other neurotransmitters on personality and mental health, and the changes in diagnosis itself with the introduction of medications for the "less mentally ill"